Valve

ABSTRACT

A bistable double-acting valve includes a valve body having two opposed compression surfaces and an elongated spring element located between the two compression surfaces and having a first end pivotally secured to the valve port and its other end secured to an actuating lever. The length of the spring is such that a smooth curve is formed between its two ends in each of the two bistable positions, and in each bistable position the spring clamps a section of tubing against a corresponding compression surface to block fluid flow through that tubing.

United States Patent [151 3,635,25 1 Gaines 1 Jan. 18, 1972 VALVE3,467,139 9/1969 Richards ..251/75 x [72] Inventor: Stanley L. Gaines,Wayland, Mass. O I PATENTS 0 APPLICATIONS Assignw InstrumentationLaboratory, g- 699,595 12/1940 Germany ..251 75 ton, Mass.

- Primary ExaminerR0bert G. Nilson [22] Filed 1970 Attorney-Willis M.Ertman [2]] Appl. No.: 27,196

[57] ABSTRAQT [52] U.S.Cl ..137/636, 137/607, 251/9, A table double-actng valve includes a val e body having 251/75 two opposed compressionsurfaces and an elongated spring 51 1m.c1 ..Fl6l5S/14, F16k 31/56element located between the two compression Surfaces and 58 FieldofSeareh ..l37/607, 636; 251/4, 5, 6, having a first 9nd Pivotallysecured to the valve P and its 251, 9 10 75 other end secured to anactuating lever. The length of the spring is such that a smooth curve isformed between its two 56] References Cited ends in each of the twobistable positions, and in each bistable position the spring clamps asection of tubing against a cor- UNITED STATES PATENTS respondingcompression surface to block fluid flow through that tubin 2,888,8776/1959 Shellman et al ..25l/9 UX g 3,450,152 6/1969 Ouellette ..25 H5 X6 Claims, 2 Drawing Figures VALVE This invention relates to valves. Inparticular, it relates to a bistable double-acting valve for controllingthe flow of fluids through two sections of resiliently deformabletubing.

It is an object of the invention to provide a novel and improvedbistable valve arrangement that will permit fluid flow through either oftwo lines, but that under normal conditions will not permit flow throughboth lines at once. Another object of this invention is to provide sucha valve that will release itself under excess pressure, thereby avoidingrupture in the line. It is a further object to provide a valve that iscapable of releasing itself with respect to one line in response to agiven excess pressure and with respect to the second line in response toa different excess pressure. Still another object is to provide a noveland improved bistable valve that is simple to make, inexpensive, andreliable.

The invention features a bistable double-acting valve for permittingfluid flow through either of two sections of resiliently deformabletubing, but not permitting flow through both sections at once. The valvehas a valve body defining first and second compression surfaces. A leveris secured to the valve body for angular motion about a pivot axis,between two extreme positions; the lever has a handle on one side of thepivot axis and a spring-receiving portion on the other side of the axis.An elongated spring element is disposed between the compression surfacesand has a first end secured to the springreceiving portion of the lever,and a second end secured to the valve body. The length of the spring issuch that a smooth curve is formed between the two ends in each of twobistable positions. The valve body has positioning means for positioninga portion of each section of tubing along a corresponding compressionsurface for compression between the spring ele ment and that compressionsurface.

Thus, when the lever is in a first extreme position, the springcompresses the first section of tubing against the first compressionsurface, constricting the tubing and preventing flow through it, whilepermitting flow through the second section. When the lever is pivoted tothe second extreme position, the spring compresses the second section oftubing against the second compression surface, constricting the tubingand preventing flow through it, while permitting flow through the firstsection.

In a preferred embodiment, the pivot axis of the lever and the secondend of the spring are parallel and define a plane; the two compressionsurfaces are generally planar and are generally parallel to and spacedequally from this plane.

The spring has two generally planar compression sides, with at least aportion of each compression side parallel to a compression surface.

The surface dimension of each compression side perpendicular to thelength of the spring element is at least as great as the larger diameterof the tubing when constricted. The length of the spring element issuflicient to form a smooth curve extending from the first end to thesecond end with at least a point within the parallel portion of thecompression side proximate to the first compression surface touchingthat surface when the lever is in the first extreme position, and toform a similar smooth curve with at least a point within the parallelportion of the second compression side touching the second compressionsurface when the lever is in the second extreme position. The twosections of tubing in which flow is controlled are connected by aT-connector to a third section of tubing downstream of the tubingsections which may be constricted by the spring.

Other objects, features and advantages will appear from the followingdescription of a preferred embodiment of the invention, taken togetherwith the attached drawings thereof, in which:

FIG. 1 is a side elevational view, with parts broken away, of a valveconstructed according to the invention; and

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1.

With reference to FIGS. 1 and 2, the valve assembly includes a valvebody 10 to which a cover portion 12 is removably secured by four screws13. Body 10 has parallel sidewalls l4 and 16, front wall 18 rear wall20, and bottom 22. Sidewall 16 has an entrance opening to admit asection 30 of tubing, and sidewall 14 has a similar opening, not shown,to admit section 28 of tubing. Rear wall 20 has two exit apertures 32and 34 for the tubing. Between the entrance openings and exit apertures,the tubing sections 28 and 30 lie parallel to sidewalls l4 and 16 andtouching them. Front wall 18 includes an opening 36 through whichoperating lever 38 extends, with handle portion 40 outside front wall 18and spring-receiving portion 42 inside. Lever 38 is secured in place bypivot pin 44 that extends through bore 46 in front wall 18. The end 48of flat spring 50, seen in FIG. 2 with narrow edge uppermost, is securedto pivotable pin 52 that extends between floor 22 and cover 12, and itsopposite end 54 is secured to the spring receiving portion 42 of lever38. Tubing sections 28 and 30 are joined by a T-connector 56 externallyof valve body 10 and downstream of the portions to be constricted. Pins58, 60 form projections in the sidewalls l4, 16 respectively.

In the valve of this invention, spring 50 has two stable positions inwhich it constricts one tube or the other. When lever 38 is in theextreme position shown in FIG. 2, spring-receiving portion 42 so orientsspring 50 that it presses against tubing section 28, compressing itagainst wall 14 and pin 58 and thereby cutting off flow within tube 28.When lever 38 is moved from the position shown to the opposite extremeposition, it pivots about pin 44, causing spring-receiving portion 42 tomove end 48 of spring 50. This releases tube 28, but since spring 50 istoo long to extend in a straight line between lever 38 and pin 52 and isresilient, it snaps across the chamber between walls 14 and 16 andpresses tubing section 30 against wall 16 and pin 60, blocking flowthrough that section.

This valve assembly therefore has two stable positions and reliably cutsoff flow in either of two tubes. It will not remain stably in anyintermediate position. Should the pressure in a constricted line becomeexcessive, however, the biasing force of spring 50 will be overcome andthe valve will open in throttling mode, releasing that section of tubingsufficiently to prevent rupture of the tubing. When the pressure isreduced, the valve will automatically reclose.

One embodiment of this invention is used to select one of two gases forcalibration of a measuring electrode. The gases flow through twosections 28, 30 of surgical latex tubing, each one-eighth inch in outerdiameter and one-sixteenth inch in inner diameter, and of 30 durometerhardness. Sidewalls 14, 16 are spaced 0.625 inch apart. Spring 50 isspring steel 2.078 inches long, 0.200 inch wide, and 0.010 inch thick,and when it is in position in the valve body, the two ends 48, 54 areseparated by 2.03l inches. This valve will not leak when the pressureapplied for tube sections 28, 30 is 15 p.s.i.

It will be appreciated that by varying the length and/or position ofspring 50, a greater or lesser section of the spring can be caused topress against the tubing, thereby providing more or less constrictingforce. Therefore, for example, if it is per missible or desirable torelieve pressure in one line at a different value than in the otherline, the spring ends may be secured at points closer to one side thanthe other, for example closer to side 14 than to side 16. In this case,spring 50 will press with greater force against side 14 than againstside 16; therefore a greater pressure in tube 28 than in tube 30 will berequired to open the valve.

While particular embodiments of the invention have been shown anddescribed, various modifications will be apparent to those skilled inthe art and therefore it is not intended that the invention be limitedto the disclosed embodiment or to details thereof and departures may bemade therefrom within the spirit and scope of the invention.

What is claimed is:

l. A bistable double-acting valve for permitting fluid flow througheither of two sections of resiliently deformable tubing, but notpermitting flow through both at once, comprising a valve bodydefiningfirst and second oppositely disposed compression surfaces,

a lever secured to said valve body for angular motion about a pivot axisand between two extreme positions, and having a handle on one side ofsaid pivot axis and a springreceiving portion on the other side of saidpivot axis, and

an elongated spring element disposed between said compression surfacesand havinga first end secured to said spring-receiving portion of thelever, and a second end the surface dimension of each compression sideperpendicular to the length of said spring being at least as great asthe larger diameter of said tubing when constricted, said spring elementbeing disposed between said compression surfaces with at least a portionof each compression side parallel to a said compression surface,

the length of said spring element being sufficient to form a smoothcurve extending from said first to said second end and having at least atangent point within said parallel portion of the compression sideproximate to said first and having a first end secured to saidspring-receiving portion of said lever, and a second end secured to saidvalve body,

the length of said spring element being sufficient to form a smoothcurve extending from said first to said second end and having at least atangent point, within said parallel portion of the compression sideproximate to said first compression surface tangent to said surface whensaid lever is in said first extreme position, and having at least aSecured to said valve body, tangent point within said parallel portionof the compresthe g i of said spring f" belng that a smooth sion sideproximate to said second compression surface bP' l fl ff bow/en two endsm of two tangent to said surface when said lever is in said second ePositions, extreme position,

Said Valve y having Poslfioning means for POBmoning said valve bodyhaving positioning means for positioning a portion of each section oftubing alonga corresponding portion of each said section of tubing forcompression assassins:assassins? w said m and 1,

' ace an ener a e t ereto, an sai two sections whereby when said leveris in said first extreme position, of tubinggbeing gognected by a Tcnnecmr to a thim said spring element compresses said first section oftubing section of tubing gf 5 first 2 g???" g f m whereby when saidlever is in first said extreme position,

m g fg g g ggi 'fi g gl gzz gai said spring gletrnent compresses firstsaid section of tubing a ainst sai rrst com ression surface at said tanent said lever is pivoted to said second extreme position, said pi tcting saidpmbing and preventing fluid flow spring element compressessaid second section of tubing therethmugh while permitting fluid flowthrough the against said second compression surface, constricting saidSecond and third Said Sections of tubing and when said i g gg i lg g grggyg i'gzggg whlle lever is pivoted to said second extreme position, said2 The vslve of claim 1 wherein said s ring element has first Springelement compresses Second said Section of tubing andsecond com ressionsides p against said second compression surface at said second p tangentpoint, constricting said tubing and preventing fluid flow therethroughwhile permitting fluid flow through the first and third said sections oftubing.

6. A bistable double-acting valve for permitting fluid flow througheither of two sections of resiliently defonnable tubing, but notpermitting flow through both at once, comprising a valve body definingfirst and second compression surfaces,

a lever secured to said valve body for angular motion about a pivot axisand between two extreme positions, and having a handle on one side ofsaid pivot axis and a springcompression surface tangent to said surfacewhen said 40 receiving Portion on the other t of said Pivot axis andlever is in said first extreme position, and having at least a an 9spnng f havmg two generally F tangent point within Said parallel portionof the cmpres pression sides, the width of each compression side beingsion side proximate to said second compression surface at as as largerf" of "f mbmg when tangent to said surface when said lever is in saidsecond cqnsmcted Sprmg elenfem bemg d'sposfid between extreme positionsaid compress on surfaces With at least a portion of each whereby whensaid lever is in first said extreme position, compress parallel to a sadcofnpresfmn f f said spring element compresses first said section oftubing and f, first and secured "8"=' against said first compressionsurface at said tangent of and level" seconfi and pw'omny Secumd point,and when said lever is pivoted to said second ex- Valve y, Said pivotaxis and said nd nd treme position, said spring element compressessecond beng Parallel deflmng a Pi and first and said section of tubingagainst said second compression second compresslon surfafes bemggenerally P surface at said second tangent point. and equally l f f P 3.The valve of claim 2 wherein said compression sides of length of said lelement i sufficient to form a said spring element and said compressionsurfaces of said 55 smooth Furl/e extefldlng from first to said secondend valve body are generally fl and having at least a tangentpornt,within said parallel 4. The valve of claim 2 wherein said pivot axis andsaid Portion f the compression side proximate to said fi st second endof said spring element are parallel and define a Pf surface 2 Surfafiewhen Said plane, and said first and second compression surface are levelf extreme Posmon, and having at least a generally parallel to andequally spaced from said plane. -"8 P Wllhln Said Para l l portion ofthe compres- 5. A bistable double-acting valve for permitting fluid flowsion side proximate to Said Second compression sul'face through eitherof two sections of resiliently deformable tubing, tangent to Surfacewhen Said level is in a d nd but not permitting flow through both atonce, comprising extreme Poslilon,

a valve body defining first and second compression surfaces, Said valvebody having positioning means for positioning a a lever secured to saidvalve body for angular motion about Portion of each Said Section Oftubing f r C mpr ssion a pivot axis and between two extreme positions,and havbetween said spring element and a said compression suring ahandle on one side of said pivot axis and a springface and g nerally Paa l t and aid tw ti ns receiving portion on the other side of said pivotaxis, and of tubing being connected by a T-connector to a third anelongated spring element having first and second comsection of tubingdownstream of said portions,

pression sides, the surface dimension of each compreswhereby when saidlever is in first said extreme position, sion side perpendicular to thelength of said spring being said spring element compresses first saidsection of tubing at least as great as the larger diameter of saidtubing when against said first compresion surface at said tangentconstricted, said spring element being disposed between point,constricting said tubing and preventing fiuid flow said compressionsurfaces with at least a portion of each therethrough while permittingfluid flow through the compression side parallel to a said compressionsurface, second said section of tubing, and when said lever is pivotedto said second extreme position, said spring element compresses secondsaid section of tubing against said second compression surface at saidsecond tangent point, constricting said tubing and preventing fluid flowtherethrough while permitting fluid flow through the first 5 saidsection of tubing. r

ii 1W i W! i

1. A bistable double-acting valve for permitting fluid flow througheither of two sections of resiliently deformable tubing, but notpermitting flow through both at once, comprising a valve body definingfirst and second oppositely disposed compression surfaces, a leversecured to said valve body for angular motion about a pivot axis andbetween two extreme positions, and having a handle on one side of saidpivot axis and a spring-receiving portion on the other side of saidpivot axis, and an elongated spring element disposed between saidcompression surfaces and having a first end secured to saidspringreceiving portion of the lever, and a second end secured to saidvalve body, the length of said spring element being such that a smoothcurve is formed between said two ends in each of two bistable positions,said valve body having positioning means for positioning a portion ofeach section of tubing along a corresponding said compression surfacefor compression between said spring element and that compressionsurface, whereby when said lever is in said first extreme position, saidspring element compresses said first section of tubing against saidfirst compression surface, constricting said tubing and preventing fluidflow therethrough, while permitting fluid flow through said secondsection, and when said lever is pivoted to said second extreme position,said spring element compresses said second section of tubing againstsaid second compression surface, constricting said tubing and preventingfluid flow therethrough, while permitting fluid flow through said firstsection.
 2. The valve of claim 1 wherein said spring element has firstand second compression sides, the surface dimension of each compressionside perpendicular to the length of said spring being at least as greatas the larger diameter of said tubing when constricted, said springelement being disposed between said compression surfaces with at least aportion of each compression side parallel to a said compression surface,the length of said spring element being sufficient to form a smoothcurve extending from said first to said second end and having at least atangent point within said parallel portion of the compression sideproximate to said first compression surface tangent to said surface whensaid lever is in said first extreme position, and having at least atangent point within said parallel portion of the compression sideproximate to said second compression surface tangent to said surfacewhen said lever is in said second extreme position, whereby when saidlever is in first said extreme positioN, said spring element compressesfirst said section of tubing against said first compression surface atsaid tangent point, and when said lever is pivoted to said secondextreme position, said spring element compresses second said section oftubing against said second compression surface at said second tangentpoint.
 3. The valve of claim 2 wherein said compression sides of saidspring element and said compression surfaces of said valve body aregenerally flat.
 4. The valve of claim 2 wherein said pivot axis and saidsecond end of said spring element are parallel and define a plane, andsaid first and second compression surface are generally parallel to andequally spaced from said plane.
 5. A bistable double-acting valve forpermitting fluid flow through either of two sections of resilientlydeformable tubing, but not permitting flow through both at once,comprising a valve body defining first and second compression surfaces,a lever secured to said valve body for angular motion about a pivot axisand between two extreme positions, and having a handle on one side ofsaid pivot axis and a spring-receiving portion on the other side of saidpivot axis, and an elongated spring element having first and secondcompression sides, the surface dimension of each compression sideperpendicular to the length of said spring being at least as great asthe larger diameter of said tubing when constricted, said spring elementbeing disposed between said compression surfaces with at least a portionof each compression side parallel to a said compression surface, andhaving a first end secured to said spring-receiving portion of saidlever, and a second end secured to said valve body, the length of saidspring element being sufficient to form a smooth curve extending fromsaid first to said second end and having at least a tangent point,within said parallel portion of the compression side proximate to saidfirst compression surface tangent to said surface when said lever is insaid first extreme position, and having at least a tangent point withinsaid parallel portion of the compression side proximate to said secondcompression surface tangent to said surface when said lever is in saidsecond extreme position, said valve body having positioning means forpositioning a portion of each said section of tubing for compressionbetween said spring element and said compression surface and generallyparallel thereto, and said two sections of tubing being connected by aT-connector to a third section of tubing, whereby when said lever is infirst said extreme position, said spring element compresses first saidsection of tubing against said first compression surface at said tangentpoint, constricting said tubing and preventing fluid flow therethroughwhile permitting fluid flow through the second and third said sectionsof tubing, and when said lever is pivoted to said second extremeposition, said spring element compresses second said section of tubingagainst said second compression surface at said second tangent point,constricting said tubing and preventing fluid flow therethrough whilepermitting fluid flow through the first and third said sections oftubing.
 6. A bistable double-acting valve for permitting fluid flowthrough either of two sections of resiliently deformable tubing, but notpermitting flow through both at once, comprising a valve body definingfirst and second compression surfaces, a lever secured to said valvebody for angular motion about a pivot axis and between two extremepositions, and having a handle on one side of said pivot axis and aspring-receiving portion on the other side of said pivot axis, and anelongated spring element, having two generally flat compression sides,the width of each compression side being at least as great as the largerdiameter of said tubing when constricted, said spring element beingdisposed between said compression surfaces with at least a portion ofeach compression side paRallel to a said compression surface, and havinga first end secured to said spring-receiving portion of said lever, anda second end pivotally secured to said valve body, said pivot axis andsaid second end being parallel and defining a plane, and said first andsecond compression surfaces being generally parallel to and equallyspaced from said planes, the length of said spring element beingsufficient to form a smooth curve extending from said first to saidsecond end and having at least a tangent point, within said parallelportion of the compression side proximate to said first compressionsurface tangent to said surface when said lever is in said first extremeposition, and having at least a tangent point within said parallelportion of the compression side proximate to said second compressionsurface tangent to said surface when said lever is in said secondextreme position, said valve body having positioning means forpositioning a portion of each said section of tubing for compressionbetween said spring element and a said compression surface and generallyparallel thereto, and said two sections of tubing being connected by aT-connector to a third section of tubing downstream of said portions,whereby when said lever is in first said extreme position, said springelement compresses first said section of tubing against said firstcompression surface at said tangent point, constricting said tubing andpreventing fluid flow therethrough while permitting fluid flow throughthe second said section of tubing, and when said lever is pivoted tosaid second extreme position, said spring element compresses second saidsection of tubing against said second compression surface at said secondtangent point, constricting said tubing and preventing fluid flowtherethrough while permitting fluid flow through the first said sectionof tubing.